#! /usr/bin/env python
#-- coding:utf8 --

import rospy
from learning_topic.msg import msg_demo

def e_Callback(data):
	rospy.loginfo("I know that %s = %f", data.name, data.value)

def listener():
	rospy.init_node('listener',anonymous=True)
	rospy.Subscriber("e_value",msg_demo,e_Callback)
	rospy.spin()

if __name__ == '__main__':
	listener()

